Short answer
The practical way to deal with ham radio interference is to fix the receiving equipment that is being affected, or to work with the operator to fix their station. Deliberately jamming or blocking radio transmissions is illegal in many countries, including the United States, and can disrupt emergency services.
Why ham signals reach your equipment
Interference from a nearby amateur station usually happens because a consumer device picks up the signal unintentionally. Cheap audio gear, TVs, cordless phones and doorbells are common examples, and the cause is often poor immunity in the device or its cables rather than a fault in the ham’s radio. Signals can enter through speaker wire, power cords or antenna lines.
Step-by-step fixes
- Identify the pattern. Does the problem happen only when the neighbor transmits? Note times and the device affected.
- Talk politely first. Many hams are glad to help and may be willing to check their station, adjust power or change antenna placement.
- Add ferrite chokes to the affected cables, such as power, audio and video. Clip-on ferrites are inexpensive and often help.
- Use filters. A high-pass filter on a TV antenna input or a line filter on power may reduce the problem. Pick a filter designed for the band involved.
- Check wiring and connections. Loose, corroded or unshielded connections can rectify signals and create noise.
- Replace or upgrade the device if it is very susceptible. Better-made equipment resists interference.
- Get a second opinion. Local radio clubs often have members who investigate interference as a service, and our Elmer article explains how to find one.
Shielding and Faraday cages
Metal enclosures can reduce radio signals, but practical shielding is harder than it sounds. Gaps, cables and openings let signals through, and wrapping a room in foil is not a reliable fix. Specially designed shielded enclosures exist, but they are unusual for household use. The most effective steps are normally filtering and cabling fixes.
Jamming is not an option
Devices that block radio signals, including signal jammers, are illegal to market, sell or use in many places, with the US FCC being one example. They can interfere with unrelated communications, including emergency calls. If you want a signal reduced, the lawful approach is to involve the operator or the regulator.
When to involve regulators
If friendly efforts and basic fixes fail, contact your national regulator. In the US that is the FCC, which has procedures for interference complaints. Keep a log of when problems occur, which devices are affected, and what you tried.
If you are the ham causing it
- Check for harmonics and keep your signal clean.
- Reduce power where a lower level still works.
- Ensure good grounding and well-made feedlines.
- Ask the neighbor to describe the problem and help test fixes.
Our beginner’s guide to ham radio covers other things new operators should know.
EMP question
Readers sometimes ask whether ham radios are EMP proof. They are not inherently protected, and I cannot give firm claims about how any specific device would behave. Some hobbyists store spare equipment in metal containers as a precaution, but results depend heavily on construction. For more on whether your own transmissions can be located, see can ham radio be traced.